EP3265772A1

EP3265772A1 - Multiple configuration wind tunnel balance and method for retrofitting the wind tunnel balance

Info

Publication number: EP3265772A1
Application number: EP16708138.9A
Authority: EP
Inventors: Anton Knestel; Christian Hartmann; Thomas Becherer
Original assignee: Maha AIP GmbH and Co KG
Current assignee: AIP GmbH and Co KG
Priority date: 2015-03-05
Filing date: 2016-03-04
Publication date: 2018-01-10
Anticipated expiration: 2036-03-04
Also published as: EP3265772B1; US20180038766A1; WO2016139325A1; US10746627B2; DE102015204020A1

Abstract

The present invention relates to a device which is a wind tunnel test stand, in particular a multiple configuration wind tunnel test stand, which can be converted with a lower level of complexity into at least a single band, three-band and/or five band configuration, thereby ensuring increased measurement accuracy.

Description

MULTI-CONFIGURATION WIND CHANNEL SCALE AND METHOD OF REMOVING THE WIND CHANNEL SCALE

The wind tunnel scale or wind tunnel test rig and the associated method described here allow a quick conversion of the wind tunnel balance, for example, from a five-band configuration into a single-volume configuration and vice versa. The wind tunnel balance described here is in particular designed such that the conversion can be carried out with an exchange of only a few wind tunnel balance components and with high process reliability and accuracy. The measurement accuracy of Windkanalprüfstandes is very high in all configurations, and in particular in a one-band and three-band configuration, and it can already be the smallest forces, for example. Of a few Newton, safely detected .werden.

During the development of motor vehicles, such as e.g. Passenger cars or racing cars, these · are usually tested in wind tunnels on their aerodynamic properties. To measure forces which act on the motor vehicle during these aerodynamic tests, different test benches or wind tunnel balances have hitherto been used, depending on the test target and type of motor vehicle. In wind tunnel cars, a large blower blows a realistic air flow onto the vehicle. To make this aerodynamically realistic, the vehicle underbody must also move at wind speed.

Known test bench types have, for example, a different number of belt units and accordingly, for example, a distinction is made between cover, three-band and five-belt test stands. The coordinate system of the test stands is selected regularly such that the X axis points in the running direction of a treadmill of the test stand / wind tunnel scale. The Y-axis is transverse to the treadmill. The Z-axis points away from the treadmill starting from the surface of an upper run of the treadmill. This coordinate system is also used in _. used the figures described below. In the case of the so-called five-belt systems, the flow on the underbody of the vehicle is simulated by a so-called intermediate belt or center belt. The middle conveyor belt here is only so wide that the vehicle wheels and the brackets (rocker supports or Rockerpanells) do not get up on the middle conveyor belt. The wheels of the vehicle stand on compact as possible separate Radbandeinheiten.

In other words, in a five-band test rig, a center band unit and laterally four smaller (wheel) band units are provided. Usually a motor vehicle is set up on the four lateral belt units and the belt units are weighed.

Five-band test stands are preferably used in the measurement or testing of passenger cars, since the mounting of motor vehicles on a five-band test bench is usually less time-consuming than on single-bed test benches. Cover test stands are particularly preferred for motor vehicles with high output forces, such as racing vehicles, which usually produce significantly higher output forces than passenger cars or series vehicles.

In competitive vehicles (sports or racing cars) the complete vehicle or a model of the vehicle is placed on a single large treadmill. This configuration is commonly referred to as a single-bay test rig (configuration) or a single belt test rig. The treadmill of the binding roll unit is wider than the (largest) vehicle width and extends longitudinally, especially behind the vehicle, beyond the vehicle.

In other words, cover test stands usually have a belt unit with a wide continuous treadmill, which rotates on two rollers or drums. The motor vehicle is positioned for aerodynamic testing with all wheels on this single treadmill (hence single bay tester) and relative thereto fixed. For this example, fixing devices can be used, which are arranged laterally to the treadmill. The wheels may be supported by bearings that may be located below the upper run of the treadmill between the rollers. The bearings may include weighing pads or the like, so that Z-forces can be detected through the belt (this is referred to as a through-band measurement).

Cover test stands are especially the preferred choice for the measurement or testing of racing sports cars, as here u.a. An accurate picture of output forces can be obtained, which are particularly important in racing sports cars of great importance.

It should be noted that the above-described through-band measurement can also be used in three-band, five-band and seven-band test stands. In Dreibandprüfständen the tires of the motor vehicle are on narrower sideband units. To simulate the running surface runs between the treadmills of the lateral belt units a so-called center band. The through-band measurement is carried out on the two lateral belt units. In five-band test stands, the through-band measurement is used in particular if the track width of a vehicle is less than or equal to the width of the center band and the motor vehicle only rests on the center band.

Various motor vehicle manufacturers are engaged in production vehicle construction as well as in the construction of competition vehicles. Since the construction of a wind tunnel with a high-performance blower entails high costs, there is a desire for a convertible / convertible test stand which allows to convert as quickly as possible from a so-called five-band system to a "single-belt system" or three-band system. It is also conceivable that the single-belt system consists of several subbands.

DE 10 2008 036 315 B4 describes a wind tunnel test bench which can be converted from a five-band configuration into a three-band configuration. On the Wheelbase units described therein can be installed, which form a five-band configuration together with a fixedly installed middle running band. The four wheel belt units can be removed and two single side belts placed on the weighing platform.

Since the large and heavy sidebands are mounted on the weighing platform, the weighing platform must carry large masses. However, this reduces the measuring accuracy of the weighing platform and the large mass that rests on the weighing platform, the self-resonance of the balance is undesirably reduced. Another very significant disadvantage is that parasitic forces or apparent forces and rolling resistance of the wheels on the sidebands can not be separated from aerodynamic forces.

DE 10 2011 085 640 describes a binding wind tunnel test bench which in particular makes it possible to separate apparent forces (for example generated by the vehicle fixing) and rolling resistance of the wheels from aerodynamic forces. The treadmill or the binding unit is floating / sliding. A movement in the X and / or Y direction is supported by a force measuring means on the weighing platform. The cover unit is decoupled with the weighing platform in the Z direction with respect to the power transmission, while such power coupling is provided for the X and / or Y direction. A disadvantage of this Windkanalprüfstandes, however, is that the system is not convertible or only with great expenditure of time, e.g. from a cover to a five-band configuration.

There is a need for wind tunnel scales or wind tunnel test rigs with which both passenger cars and racing sports cars can be tested without having to forego the advantages of the respective test bed types or test bed configurations, especially one-band, three-band and five-band configuration, and one in all configurations highest possible accuracy in the measurement of forces. The However, having two (or more) different test rig types in different wind tunnels is very costly and thus uneconomical.

Consequently, there is a need for a wind tunnel tester or a wind tunnel scale and an associated method, which allows to be converted from one Prüfstandart to another Prüfstandärt with relatively little time and construction effort, the measurement accuracy is as high as possible in each configuration. In other words, there is a need for a method and a wind tunnel scale that has various configurations in terms of the number of belt units and that provides very high measurement accuracy, along with the ability to quickly and safely perform a change between configurations.

The object is solved by the invention according to the independent patent claims. Further preferred developments are described by the dependent claims.

One aspect of the invention relates to a wind tunnel test rig. Preferably, this may be a multiple configuration Windkanalprüfstand that can be converted at least in a one-band, three-band and / or five-band configuration.

The wind tunnel test rig can frame a test stand for receiving forces that can act, for example, on a motor vehicle to be tested, as well as a (weighing) platform. The weighing platform can be mounted relatively movable to the test rig frame.

The relative movement of the weighing platform relative to the test bench frame can be realized in particular by two preferred options. Thus, elastic components may be provided, which allow a (possibly only very minimal) spring travel as a relative movement. These elastic components may particularly preferably be force-sensing means which can detect the transmitted force. Another way to allow a relative movement, it may be a allow at least within a predetermined amplitude of movement free relative movement. In contrast to a relative mobility, in particular a (rigid) (motion) coupling is to be considered, which does not allow a relative movement over a free distance or a spring travel. With spring travel can here also a small deformation, as it performs, for example, a piezoelectric material under pressure, meant.

In other words, "relatively moveable" may be understood to mean free mobility in the corresponding direction and relative to said second component Alternatively or additionally, "relatively movable" may also mean that at least one force sensing means is disposed between the two relative to one another is provided movable components / components. For example, in a particularly preferred embodiment, the relative movability between the test rig frame and the weighing platform can be achieved by virtue of the fact that the weighing platform can be connected to the test rig frame in the X, Y and Z directions via at least one force detection means. Another example would be a slide explained in more detail below, for example. In X-direction characterized relative movable to the test frame can be stored frame that these two components in this (X) direction by means of at least one force sensing means are interconnected.

Furthermore, at least one force detection means, which can be arranged between the weighing platform and the test stand frame, be provided in order to be able to detect, for example, forces between weighing platform and test stand frame. The force sensing means may preferably comprise load cells and / or strain gauges. With the help of the force sensing device (s), forces can preferably be transmitted as well as detected. By arranging one or more force detecting means between the platform and the test stand frame, for example, the forces occurring / transmitted between these components can be detected, which in particular can result from forces which can act on the vehicle, on the belt unit or on the treadmill. Furthermore, the wind tunnel test rig can have at least one belt unit with two rollers and a treadmill wrapped around it. In the case of wheel belt units, sideband units and binding unit, this belt unit can be provided for setting up at least one motor vehicle wheel of the motor vehicle to be tested. On a center belt unit regularly no wheels are set up, as this particular is to simulate the road. This tape unit (s) may, for example, comprise at least one tape unit frame on which the treadmill may be arranged, which may be looped around the at least two rollers.

The tape unit (s) can be designed differently depending on the configuration. Thus, a cover unit of a cover configuration may be wider and longer than the vehicles to be tested / tested. Sideband units of a three-band configuration can be relatively narrow (so that the wheels can be set up) and longer than a motor vehicle. A center belt unit may be longer than a motor vehicle to be tested and narrow enough that the wheels protrude right and left across the width / side edges. Wheel belt units of a five-band configuration can be relatively compact, so that a wheel of a motor vehicle to be tested can be turned off. Preferably, the three-band configuration can simulate a binding configuration, with the two side bands and the center band together being able to assume the technical function of the individual band of a binding configuration. It is advantageous in a three-band configuration that the sideband units each weigh less than a single-band unit, so that the sideband units can be moved or installed and removed with less effort.

Furthermore, the test stand may comprise a carriage for receiving at least one belt unit. Particularly preferably, the carriage can receive or store a band unit of a binding or three-band configuration. This should mean in particular that the corresponding belt unit can be placed on the carriage. Very particularly preferred may be to another Attachment of the tape unit on the carriage are omitted (but it is possible), since the tape unit already stands up safely on the carriage due to the weight. If an attachment should be provided, then in particular self-performing mounting options are preferred, such as form-fitting fasteners which engage with each other when the tape unit is placed on the carriage.

The carriage can preferably be mounted in the X and / or Y direction relatively movable to the test rig frame. This can preferably be achieved by means of a floating bearing on which the carriage can be mounted. Such a floating bearing can divert forces in the Z direction into a bearing base, e.g. in a foundation, the test rig frame or the like - depending on where the floating bearing stands. The floating bearing can also allow the smoothest possible movement in the other spatial directions, in particular the X and Y directions, which can be limited or prevented by constructive measures, a movement in one of the two aforementioned directions. The floating bearings may include, for example, plain bearings, fluid bearings and / or roller bearings.

The relative movement that the carriage can make with respect to the bench frame may preferably be a displacement. Particularly preferably, the carriage can be mounted in one of the X and / or Y direction via a minimum elastic travel relatively movable to the test rig frame. The minimum travel can be particularly preferably the spring travel of a force detection means that can be arranged along the corresponding direction between the test rig frame and slide in order to detect forces transmitted over it.

In other words, the carriage mounted as frictionless as possible can be used to accommodate the weight of a cover unit of a cover configuration or sidebands or side band units of a three-band system. The carriage is largely frictionless, ie floating, stored (in the X and Y directions). Furthermore, it is advantageous that the carriage can remain in the test bench at any time. The carriage may allow the three-band sideband units and the cover unit not to be placed with their weight on the weighing platform, resulting in improved measuring accuracy. In the five-band configuration, the carriage can be left in the system, so that the conversion takes less time and effort.

In summary, the wind tunnel tester has, so to speak, (at least) a 3-in-1 configuration, i. a wind tunnel scale, which can be converted, for example, from a five-band to a three-band or Einbandprüfstand or vice versa with little time and effort. The carriage makes it possible to absorb the weight of at least the cover tape unit in the cover configuration and at least the sideband units in the three-band configuration and to discharge it off the weighing platform. At the same time, a force-like coupling (apart from forces in the Z-direction) with the weighing platform is made possible so that forces can be conducted / supported in a predetermined or desired direction on the weighing platform. The placement of the cover unit or the sideband units on the frame can be done with relatively little installation effort, so that a change of configurations can be facilitated and accelerated.

Furthermore, the carriage can be coupled to the weighing platform in the X and / or Y direction (rigidly) such that a relative movement between the carriage and the weighing platform in the associated direction can be prevented (or rigidly). Here, the associated direction should mean that, for example, when there is a (rigid) coupling in the X direction, a relative movement in the X direction is excluded, ie the two units, weighing platform and slide, then move in the X direction in the composite. If no coupling or elastic coupling is used, the mounting of the carriage preferably permits relative movement in the X and Y directions. An above-mentioned (rigid) coupling can be achieved, for example, with a connecting device that can couple the weighing platform and the slide with each other. Particularly preferably, the connecting device can couple the two components with each other as frictionless as possible.

If e.g. a coupling in the Y direction, which may be particularly preferred made so, for example, guides, plain bearings and / or roller bearings can be arranged on side parts of the carriage and the weighing platform, which prevent relative movement of the two components in the Y direction, but a allow frictionless movement of the weighing platform relative to the carriage or the carriage to the weighing platform in the X direction. In this case, in other words, the carriage preferably prefers largely frictionless, i. floating, being stored: in the Z-direction the carriage stands on a bearing and transmits forces in the Z-direction into the bearing; in the Y-direction, the carriage is connected / (rigidly) coupled to the weighing platform. In the X direction, the carriage and the belt unit (s) thereon may move freely or elastically (relative to the weighing platform). The X-direction can, for example, be fastened to the weighing platform by means of an additional measuring device, which will be described below and which, e.g. Ventilation losses, rolling friction losses and the like. Can capture. Supply lines for hydraulics, electricity, water and the like. May preferably remain bolted to the mounted carriage. The tape unit (s) can be connected to the media (accesses) only when placed on the carriage by their weight force.

Other coupling means or connecting means may comprise guide rods or air bearings. Furthermore, hydrostatic and / or pneumatic bearings may be provided. Hydrostatic bearings are, for example, all types of bearings that allow essentially frictionless storage by means of oil or water pressure. Pneumatic bearings include eg air pressure bearings. A guide pin (piston, rod or means) can be used, which slides without friction in a guide receptacle and can be positioned eg hydraulically or pneumatically in the Z direction. The Guide receptacle can be designed depending on the shape of the guide pin and depending on the required power transmission direction. In the case of a substantially cylindrical guide pin and a desired force transmission between the belt unit or slide and platform in the X and Y directions (eg rigid X and Y couplings), the guide receptacle may preferably be essentially a cylindrical bore or recess.

Furthermore, the (rigid) coupling can cause the coupled compound of carriage and weighing platform (global) forces transmits to the test bed platform. Thus, in the case of a (rigid) Y-coupling, a relative movement of said composite to the test bench platform can be detected by means of force detection means and the transmitted force can be detected. If a relative movement is permitted between the weighing platform and the carriage, then a force (relative or internal) can be made visible by means of a gripping force which, in the case of a rigid coupling, would not be able to be displayed as an internal force. For example, a structure with rigid Y-coupling and additional Störkraft-detection means in the X direction may be suitable to detect or visualize X-by-wheel forces in addition to the "global" X forces Wheel forces may include ventilation or wheel friction losses at the wheels of the motor vehicle.

The relatively movably mounted carriage can thus make it possible that large masses of the belt units do not stand up directly on the weighing platform, so that the measuring accuracy of the test bench is increased and the natural frequencies are not lower. In addition, internal forces can be visualized, cut free as it were, and a fast change of tape units / configurations can be made possible. The quick change is u.a. allows the tape units are set up directly on the slide and can be dispensed with a further attachment.

In a cover configuration, a cover tape unit may be placed on the carriage. Cover units have particularly large masses that are no longer due to the weight of the present invention due to the present invention get up the weighing platform, as is usual in known wind tunnel scales.

In a three-band configuration, at least two sideband units can be arranged on the carriage, which likewise have relatively large masses. In addition, optionally, the center band unit of a three-band configuration can be set up on the carriage.

In the three or five band configuration, a center band unit may be provided between wheel band units of the five-band configuration or side band units of the three-band configuration. The wheel belt units or sideband units are usually provided to park the wheels of the motor vehicle to be tested on it. The center tape unit can be placed on the carriage, especially in the case of the three-band configuration. Furthermore, the center band unit can also be stored stationary. Stationary here means that the storage is fixed in all spatial directions, i. no relative movement / movement in one direction is possible. Stationary may in this context mean that the center band unit can stand up on a foundation of a wind tunnel / test bench or that the center band unit can be arranged on the test bench frame. The test stand frame can be rotatably mounted to a foundation, the center belt unit would be stationary in this case only to the test frame. The fixed storage has the advantage that no aerodynamic forces are introduced into the weighing platform or the carriage, i. there is a force decoupling.

The center band unit can also be set up on the slide in the case of the 5-band system.

The carriage may divert forces into an environment in the Z direction and be slidably mounted in the X and Y directions. It can, for example, one (or more) above-described floating storage used for storage of the carriage, which can be arranged frame, for example, on the foundation of the test bed or the test rig. In other words, the term "Environment" means that the carriage absorbs Z forces, in particular weight forces, and does not transfer them to the weighing platform.This bearing has the advantage that the masses of the belt units or of a part of the belt units that are not considerable for the test are not even measured so that these masses, which may be large, also can not reduce the measurement accuracy.

The weighing platform may have at least two sub-platforms, which may be separable from each other. These at least two sub-platforms may be interconnected in a five-band configuration of the wind tunnel test rig. In a three-band or cover configuration of the wind tunnel test rig, the first (upper) sub-platform can preferably be separated from the second (lower) sub-platform and preferably be removed from the test bench.

At least one wheel-belt unit and a fastening device for the five-band configuration, preferably preinstalled, can be arranged on the first sub-platform. Particularly preferably, in a five-band configuration, four wheel belt units can be arranged on the first sub-platform. A wheelbelt unit is compared, e.g. to a binding unit or a center belt unit, constructed substantially compact and dimensioned so that a wheel of a motor vehicle can be parked on an upper strand.

The conversion becomes even less complicated and complex due to the divisible and separable weighing platform. The (preferred upper) first sub-platform preferably holds all necessary structures, such as e.g. Wheel unit assemblies and fixture (s) already pre-installed on a surface so that these assemblies can all be assembled together (simultaneously) with the installation of the first sub-platform.

Particularly preferably, the first sub-platform with the structures arranged thereon is also already pre-weighed, so that this weight value is already known. In particular, the second sub-platform is used alone (without the first sub-platform) when a single-band or three-band configuration is to be used. In the binding configuration, a large binding unit with all associated frame parts is mounted on the upper part of the frame of the test stand and preferably held in position only on the basis of the weight. The same applies to the sideband units of the three-band configuration. In other words, the divisibility of the weighing platform allows retrofitting to be carried out with essentially two (main) steps: (dis) mounting the binding unit / three-band units and (de) mounting the first sub-platform with the pre-assembled bodies. This can be done within a short time and without complex intervention by fitters.

The at least one wheel-belt unit and fastening device (s) can be displaceably and particularly preferably arrested mounted on the first sub-platform. In other words, the wheel-belt unit (s) and / or the holding device (s) may be slidably mounted (as frictionless / low as possible) on the first sub-platform so that they are adapted to the dimensions of the motor vehicle quickly and inexpensively by means of displacement can be. A lockability allows a fixation in the desired position is possible.

The weighing platform can have at least two sub-platforms, which can be mounted separably. At least one wheel-belt unit and one fastening device of the five-band configuration can be pre-installed on the first sub-platform. The at least two sub-platforms may be interconnected in a five-band configuration of the wind tunnel test rig. A first sub-platform may be separated from the second sub-platform in a three-band or one-band configuration of the wind tunnel test rig, and more preferably be removed from the test bench. This construction, as explained above, allows a particularly fast changeover since the upper first sub-platform can already hold all (additional, alternative) necessary components for a five-band configuration. Thus, it is possible to switch between the single-band and five-band configuration particularly quickly and with very little effort, ie between the two most frequently used configurations with regard to Racing and passenger cars.

Furthermore, the wind tunnel test rig can have at least one fastening device. This may be adapted to hold a motor vehicle in / at a predetermined position on the treadmill. In a five-band configuration of the wind tunnel test rig, the fastening device can be arranged on a first sub-platform of the weighing platform. In a three-band or cover configuration of the wind tunnel test rig, the fastening device can be arranged on a second sub-platform of the weighing platform.

The fixation of the motor vehicle allows a secure holding the motor vehicle at a predefined position, so that no incorrect measurements or parasitic forces are generated by the fact that the motor vehicle leaves this position, for example. Under the action of force or deviates from it. In other words, "holding" the vehicle on the treadmill means that the vehicle maintains its predetermined position on the treadmill during aerodynamic or other attempts, i.e. does not deviate from that position.

The fastening device (restraint system) of the binding and three-band configuration can consist, for example, of two fastening supports or rods (first fastening means), which can each be arranged laterally of the treadmill. Further, it may include retaining means (second fastening means), such as e.g. Ropes, straps, straps, rods and / or combinations thereof include, which may be arranged on the mounting posts and further example, by means of recordings on corresponding receptacles on the motor vehicle frame can be arranged. A (fixed) arrangement of the fastening device on the platform can be realized, for example, non-positively and / or positively.

In particular, and particularly preferably, the fastening device on the second sub-platform can be detachably or detachably connected to it, in this way that the fastening device can be removed when converting to a five-band configuration, if this should be desirable for reasons of space.

The first and second sub-platforms can comprise at least one predefined (mechanical or force) coupling interface, whereby at least X, Y and Z forces can be transmitted between the first and second sub-platforms via this coupling interface. Furthermore, connections for the transmission of fluidic media and / or electrical currents can also be provided at the one or more coupling interfaces. Furthermore, separate coupling interfaces for fluidic media and / or electrical currents can also be provided.

The (force) coupling interface (s) may be in the simplest case, a predefined planar surfaces, which may each be arranged on two opposite surfaces of the two sub-platforms; in such a way that they rest on each other in the mounted state. The coupling interfaces may also include feet, protrusions, pins, or the like, which may come to rest or engage with an opposing surface or depression of the other sub-platform. In addition, alignment devices can preferably also be provided which bring about an automatic alignment of the two platforms with respect to one another when they are coupled together / connected to one another. This can e.g. small roles that roll at predefined levels of the other sub-platform and thereby effect an alignment. The power transmission interfaces may also include (self-acting) latching elements which latch when meshed - e.g. at a pin and well solution.

The interface (s) or connections for the fluidic media may preferably have automatic quick-release couplings. For the transmission of electrical current, coupling interface (s) or connections can be mounted to slide in a self-aligning manner, ie the plug elements can be displaceably mounted, for example, so that they can be displaced due to the shaping of guide surfaces or the like. self-aligning can slide on each other.

Further, the force sensing means, which may connect the weighing platform and the test rig frame, may be disposed on the second sub-platform. Preferably, at least force detection means are provided with which Z forces can be detected. These allow in particular the detection of weight forces and buoyancy and output forces that occur or vary during the tests. Particularly preferably, further force sensing means can be provided between the test rig frame and the second sub-platform, with which X and / or Y forces can be detected, so that e.g. also lateral forces can be displayed. The attachment to the second sub-platform has the advantage that can be saved in a conversion of the exchange or the transfer of force sensing means, which further accelerates the conversion.

An X-force measuring means may be arranged such that a force in the X-direction between the weighing platform and the test rig frame is detectable. A Y-force measuring means may be arranged such that a Y-direction force is detectable between the weighing platform and the test rig frame, and a Z-force measuring means may be arranged to detect a Z-direction force between the weighing platform and the test rig frame is.

The force measuring means can detect, for example, a small relative movement between the weighing platform and the test bench frame as a path change and output as a force value. Thus, the detection of forces is enabled separately for each measurement direction. The force values can be forwarded to an evaluation unit, eg a computer. The force measuring means (or force sensing means) may be, for example, load cells, which convert based on strain gauges, piezoelectrically or piezoresistive a path change, strain, compression, stress and / or pressure in an electric force signal. The force measuring medium can each be arranged between two buckling rods, so that only forces are directed normal to the buckling direction on the force measuring means. The buckling rods may have, for example, formations / notches, the For example, are arranged rotated by 90 ° to each other to direct essentially only forces in the normal direction to the rod axis on the load cell.

Further, an interfering force detecting means may be arranged between the carriage and the second sub-platform, in particular for detecting X and / or Y forces. The disturbance force detection means may be arranged between the carriage and the weighing platform such that a force between the weighing platform and the carriage in the X direction can be detectable, so that a ventilation loss, a rolling friction loss, aerodynamic losses between treadmill and motor vehicle and the like are detectable. The losses can be isolated or recorded separately, for example by detecting a small relative movement between the carriage and the weighing platform, so that the measuring accuracy of the entire wind tunnel balance can be further increased. The disturbance force detecting means is preferably arranged on the weighing platform in addition to the X, Y and / or Z force measuring means.

Below a top run of the at least one treadmill of a belt unit may preferably be arranged a bearing, wherein the bearing may very preferably be a weighing pad. The weighing pad may be arranged such that the motor vehicle, when it is fixed on the treadmill, rests on the treadmill with the vehicle wheels above the at least one weighing pad. Furthermore, the at least one weighing pad can detect forces in the Z direction, in particular the weight force of the motor vehicle and up and / or down forces. The optional weighing pads, which typically can be connected to a measuring sensor, can therefore, for example, force in the Z-direction, e.g. the weight of the motor vehicle and up or down forces capture.

The weighing pads detect the wheel contact forces and, after their summation, the sum of the Z forces, ie vehicle weight force, buoyancy and output forces and parasitic forces in the Z direction. Furthermore, by detecting a deflection of the weighing pads from the zero position, additional moments about the X and / or Y axis can be detected. Weighing pad here means any Measuring device, which can be used to measure Z forces, in particular for Durchbandmessungen. Preferably, one weighing pad is provided per vehicle wheel, ie, four weighing pads are generally provided.

The fastening device can hold the motor vehicle on the treadmill in a fixed position, in particular above the at least one weighing pad. The fastening device can be designed so that forces in the X, Y and / or Z direction can be transmitted from the motor vehicle via the fastening device to the weighing platform. Particularly preferably, the wind tunnel balance by means of a Z-force measuring means can detect parasitic Z forces separately, which are transmitted via the fastening device and the weighing platform to the Z- force measuring medium. This allows parasitic Z forces contained in the weights of the weighing pads to be detected separately, namely with the Z force measuring means.

Furthermore, the invention comprises methods for converting a wind tunnel test rig according to at least one of the above-explained aspects and examples. Conversion from a three- or one-band configuration to a five-band configuration may first include the step of lifting and removing the cover unit of a cover configuration, or sideband units (and possibly the center tape unit) of a three-band configuration from the carriage. Thereafter, the first sub-platform with pre-installed wheel units and mounting device on (the coupling interface) of the second sub-platform can be set up. Further, the center belt unit can be positioned between the wheel belt units. The wheelbelt units can also be placed individually on a non-divisible weighing platform.

For conversion from a five-band configuration to a three-band or one-band configuration, the first sub-platform with the pre-installed wheel-band units and the attachment means of the coupling sub-stile of the second sub-platform can be raised and removed. The cover unit can then be placed on the upper frame member. In case of a Three-band configuration, the center band and the sidebands instead of the cover unit can be set up.

The conversion according to the above-described methods can be done without major intervention by installation personnel and can be carried out quickly, so that can be achieved by the wind tunnel users significant cost savings.

In summary, the wind tunnel test bench and the retrofitting methods described have considerable advantages with regard to the versatility and usability of the test bench, since it can be transformed quickly and inexpensively into various configurations for various test purposes. Furthermore, the wind tunnel test stand according to the invention can have the advantage that an increased measurement accuracy can be achieved. Parasitic Z forces can be detected separately, in particular in the three-band and binding configuration, and the considerable weight of the wind tunnel balance can be derived from separate bearings, ie not via the weighing platform. The weighing platform can be mounted to be relatively movable or elastically supported by means of force detection means to the test stand frame. The weight of the belt unit and a (force) vehicle standing on it can be supported against the carriage. Furthermore, the measurement accuracy, in particular in the three-band and cover configuration, can be increased by the fact that parasitic forces in the Z direction can be detected separately by means of the Z force measuring means which can be arranged between the weighing platform and the test frame. The term belt unit frame may, for example, comprise all components which form the basic structure on which, for example, the rollers of the belt unit and the treadmill can be arranged. The tape unit frame may be in one or more parts. Typically, each one tape unit may essentially comprise one tape unit frame, one treadmill, and two rollers. It may be added more tape unit components, such as a drive means for driving the treadmill, hydraulic systems, electrical, etc, which will not be further explained here. The apparatus and the associated apparatus described hereinbelow will be described by way of example with reference to the accompanying schematic drawings. Show it

1 is a plan view of a wind tunnel scale in five-band configuration,

Fig. 2 is a side view of a Windkanalwaage- in

Five band configuration,

3 is a plan view of a wind tunnel scale in three-band configuration,

4 is a side view of a wind tunnel scale in three-band configuration,

Fig. 5 is a plan view of a wind tunnel scale in binding configuration and

6 shows a side view of a wind tunnel scale in a cover configuration.

In the following, various examples will be described in detail and with reference to the figures. Identical or similar elements in the figures are denoted by the same reference numerals. However, the present apparatus and method are not limited to the described combinations of features. Rather, other modifications and combinations of features of various examples are intended to be included within the scope of the independent claims.

In Figures 1 and 2, the constellation or configuration of a five-band design is shown in plan view. On the (optionally rotatable) test bed frame 1a (FIG. 2), a weighing platform 2 is mounted which detects forces in the X, Y, Z direction with force detection means 4, wherein the Z force sensing means 4a can also support the weighing platform 2. Directly on the weighing platform 2, more precisely on an upper first sub-platform 2a, are wheel-belt units 31 and sill supports / rocker panel 5b Fastener 5 pre-assembled.

The preassembled fastening device 5 as well as the four wheel belt units 31 for parking one wheel R of a motor vehicle F all allow the upper platform 2a, which is separably connected to the second, lower part platform 2b, to be quickly completely installed. It is only necessary to park the first sub-platform 2a on the lower, second sub-platform 2b. For this purpose, optional coupling interfaces 6 can be provided, which can allow a defined and reproducible docking of the upper, first sub-platform 2a.

FIG. 2 shows these coupling interfaces 6 schematically as flanges. Preferably, no further attachment with aids, such as e.g. Screws or the like., Required. The two sub-platforms 2a, 2b are due to the weight of each other safely. However, in order to enhance safety or in particular, positive-locking structures may be provided, which may be e.g. prevent relative slippage. Here, for example, mandrels or mold projections could be provided which can engage in correspondingly shaped recordings.

Furthermore, the weighing platform 2 is laterally connected to the test stand frame 1a via Y force measuring means 4c (see FIG. 1), which are arranged on a lower section of the second sub-platform 2b, as shown particularly in FIG. A (relative) movement of the weighing platform 2 in the Y direction is thus detected by the Y force detection means and the forces in the Y direction can be measured. Likewise, an X-force detecting means 4b is arranged between the test bench frame 1a and the weighing platform 2, which can accordingly detect an X force between the weighing platform 2 and the test bench frame la.

The platform is by Z-force measuring means 4a - shown are only two, but especially three or four preferred - stored in the direction of the vertical axis (Z direction) in the test bench frame la. Detected forces can be displayed, for example, by means of an evaluation unit (not shown). The forces along the travel axis (X- Forces) are detected with the at least one X-force measuring means 4b. The forces transverse to the driving axis (Y forces) are detected / measured with at least one, preferably two, Y force measuring means 4c. Two Y force measuring means 4c may be provided, which are arranged laterally on the platform 2 (the second sub-platform 2b) and spaced apart in the X direction. The opposite end of the Y force measuring means 4c is firmly connected to the test stand frame 1a.

Schematically, all force measuring means 4 are shown as simple spring elements in the figures. In the real arrangement are preferably load cells or strain gauges (or integrated into load cells Dehn strain gauge used) (other force measuring devices are also possible), which are arranged centrally in one or between two buckling bars or columns. An alternative attachment or arrangement of the force measuring means 4 is of course also possible.

The weighing platform 2 is, for example, a component which can be arranged centrally in the test bench frame la. The distances between the weighing platform 2 and the test bed frame 1a shown in FIG. 1 serve to better illustrate, i. It can be provided much smaller or larger distances. The shape of the weighing platform 2 can be plate-like with a substantially rectangular basic shape as shown in FIG. However, a more complex shape of the weighing platform 2 is also possible according to the invention. The weighing platform 2 does not necessarily have to be plate-shaped. This also applies to the two sub-elements or sub-platforms 2a, 2b of the weighing platform 2.

The fixing device 5 already explained above, which is mounted in a locked manner on the first sub-platform 2a, is provided in particular for keeping the motor vehicle F securely in the predetermined position on the treadmill 3b.

The first sub-platform 2 a is firmly connected to the second sub-platform 2 b, so that forces from the motor vehicle F can be directed to the weighing platform 2 and detected there by means of the force detecting means 4 described above can. The fixed connection between the two sub-platforms in particular already results from the weight force with which the first sub-platform 2 a reliably rests on the second sub-platform 2 b.

A shown in Figure 2 in side view carriage lb is connected via an additional measuring means with the reference mark 11 on the weighing platform 2. The carriage 1b will be explained in more detail in connection with the following figures.

Furthermore, both Figures 1 and 1 also show a center belt unit 32 which is disposed between the wheel belt units 31 and provides a long running belt 3b which rolls around the rollers 3c of the center belt unit 32. This center band simulates the road surface of the motor vehicle F to be tested, which rolls off between the wheels R. The rollers 3c of the center belt unit 32 are suspended in a belt unit frame 3a.

In addition, Figure 2 shows that the wheel band assemblies 31 have bearings 10 for wheels R below the treadmills, i. below the wheel R, may have. The wheel assemblies 31 may instead of the conventional bearing 10 for wheels have so-called trapezoidal bearings that support the upper run of the respective treadmill 3b.

It should be noted here that FIG. 1 shows a five-band system in plan view and with drawings-related openings. The breakthroughs are to enable the forces arranged under the treadmill 3b to be detected, in particular 4b and 11. Of course, these (graphic) breakthroughs do not exist in reality.

Furthermore, it should be noted with regard to Figure 1 that a one-sided arrangement of Y-force measuring means 4c is shown and this may already be sufficient to make an accurate measurement can. Furthermore, it can be seen from the schematic drawing that the weighing platform 2 is laterally (in the Y direction) in each case at least as far beyond the outer lateral edge of the / treadmills 3b that on the protruding portions mounting brackets 5a a fastening device 5 of the binding or three-band configuration can find space or can stand out.

3 and 4, a treadmill arrangement is shown which can simulate a so-called "single-belt" by means of two side tread bands 33. In other words, the figures show a three-band configuration., As shown in FIG. 4, only the side tread bands 33 are preferred The center conveyor belt 32 is stationarily supported on a foundation or the frame 1a via the bearings 3d It is also possible for all three belt units 32, 33 to be mounted on the carriage 1b.

With regard to the mounting of the lower, second sub-platform 2b, there is preferably no difference to the above-described five-band configuration. However, the first sub-platform 2a has been removed from the test bench 1, so that the coupling interfaces 6 can remain unoccupied. The motor vehicle F is held on the treadmill 3a instead of sill supports 5b by a holder / restraint system 5a. This has the two mounting brackets 5a shown a, which are preferably fixed in the Z-direction laterally to the treads 3b of the Seitenbandeinheiten 33 (in respect of the X direction preferably central position of the Windkanalprüfstandes) on the second sub-platform 2b. The fastening supports 5aa are (positionally) fixed, but preferably detachable, connected to the platform 2 or the second part platform 2b.

Furthermore, Figures 3 and 4 show that the Z-direction upper ends of the mounting brackets 5aa project beyond the Z-height of the upper run 3ba of the treadmill 3b. Preferably, in the protruding end portion of the mounting brackets 5aa at least a second fastening means 5ab is attached. The second attachment means 5ab is preferably a cable, a belt, a very thin rod or an assembly of various components such as ropes, straps, etc. and may have a receptacle at the end, which is arranged towards the vehicle F. Preferably, at least for each vehicle side (in the Y direction), two second fastening means 5ab are provided, which are arranged by means of a receptacle on corresponding receptacles on the motor vehicle F. The second attachment means 5ab hold the vehicle F in a predetermined position on the (relative to) treadmill 3b. Occurring on the ropes X- / Y-forces can preferably discharged through the ropes and act as internal forces.

If, for example, the second fastening means 5ab are not guided exactly in the horizontal, then parasitic Z forces may result which can be detected by at least one weighing pad 9 below the upper run 3ba of the moving belt 3b. Furthermore, these parasitic Ζ-forces can also separately / separately via the fastening device 5a to the Z-force measuring means 4a are passed. This allows a compensation / correction of the measured Ζ-forces on the weighing pad 9 and the Z-force measuring means 4a and thus an increased measurement accuracy.

The weighing pads 9 are arranged in Figure 3 below the treadmill 3b and characterized in the figure by means of schematic squares. The weighing pads 9 detect a Z-force by means of Durchbandmessung.

Furthermore, FIG. 4 shows that an additional force-measuring means 11 is connected to the weighing platform 2. This allows the separation of aerodynamic disturbing forces, which may result, inter alia, from the entrained with the treadmill 3b air, and forces occurring at the wheels, such as roll, Walk and / or ventilation losses, which are measured at this Störkraft-detection means 11. The further aerodynamic forces continue to be available on the force-measuring means 4 described above. Concretely, it is shown that another position is possible at a front end in the X direction) of the second sub platform 2b, the disturbance force detecting means 11 is fixedly mounted. The second end of the Störkraft-detecting means 11 is arranged in contrast to the other force measuring center in Fig. 4 at the pouring lb. Here at one of the shown side or pillar elements of the carriage lb. Thus, for example, a detection of the relative movement in the X direction between the weighing platform 2 and the Band unit 3 may be possible, which allows an additional and separate determination of the ventilation losses at the wheels of the vehicle F. These ventilation losses can, for example, be offset against the other recorded force values in order to increase the measuring accuracy of the wind tunnel scale.

As shown particularly in FIG. 4, the carriage 1b supports the sidebands 33. The carriage 1b is supported in the Z direction via floating bearings 8 on the foundation, while in the Y direction a coupling is provided by means of so-called Y bearings 7a of a connecting device 7 Weighing platform 2 before. The vehicle holding system or the fastening device 5 is also fastened to the weighing platform 2 or the lower sub-platform 2b. The connecting device 7 is the same as that shown in FIG. Lateral bearings 7a, which allow friction-free relative movement between the sub-platform 2b and the carriage 1b, are part of the connecting device 7 or form these. This achieves a (rigid) coupling in the Y direction. The bearings 7a of the connecting device 7 are shown as plain bearings, fluid bearings and / or roller bearings on side parts of the carriage lb and the weighing platform 2 arranged. The connecting device 7 allows a coupling in the Y direction and prevents relative movement of the two components (weighing platform 2 and lower sub-platform 2 b or weighing platform 2) in the Y direction. In the X-direction, however, a frictionless relative movement between the weighing platform 2 and the carriage 1b can take place, i. this will not be stopped. Consequently, there is a rigid coupling in the Y direction between carriage 1b and sub-platform 2b.

Further, Figures 5 and 6 show the constellation "single-belt." The storage of the individual components and the structure are comparable to the above-described three-band configuration the upper part of the weighing platform 2, ie the second sub-platform 2b, has been removed together with the wheel-band units 31 and the fastening device of the five-band configuration. The carriage 1b is supported (as can be seen in particular from the top view of FIG. 5) that the carriage 1b can move relatively (in the X direction) (via the force detection means shown); Both to the test bed frame la and the weighing platform 2. The floating on the floating bearings 8 mounted carriage lb is coupled via the Störkraft-detection means 11 to the weighing platform 2, so that a relative movement between these two components with respect to the case Force can be detected, if desired. The vehicle holding system 5 is non-positively connected to the weighing platform 2. While the carriage 1b is supported on the foundation in the Z-direction, ie vertically, the friction-free bearings 7a (see Figure 5) are supported on the weighing platform 2 in the Y-direction. This makes it possible that on the weighing platform 2, the (global) aerodynamic forces in the Y direction, z. B. by oblique flow, are detected. Via the disturbance force detection means 11, which connects the carriage lb or the single-belt with the weighing platform 2 in the X direction, the possibility is created, the wheel frictional forces of the forces that the weighing platform 2 detects in the X direction, to separate and thereby visualize.

It should again be noted that the cutouts and apertures of FIG. 5 are merely due to drawing, so that the components / components of the test stand 1 arranged in particular under the treadmill 3b can be made visible.

It should also be noted that the connecting device 7, which couples the weighing platform 2, 2b with respect to the Y direction to the carriage 1b (rigidly), comprises sliding or roller bearings with four individual individual bearings 7a arranged laterally on the second part platform 2b is. The friction-free bearings 7a of the connecting device 7 can also be designed as a kink bearing, ie the bearings then consist of rods or columnar supports which have two, for example, 90 ° to each other in the axial direction twisted Querschnittsverjüngungen (notches, recesses). It can also be provided more than two cross-sectional tapers per carrier. The Movement amplitude will usually be more limited in a bearing with kink straps, as in sliding or roller bearings.

In other words, in the case shown, the connecting device 7 allows a relative movement between the weighing platform 2 and the carriage 1b in the X direction. X forces can be detected on the one hand by means of the X-force measuring device between the test bed frame la and the weighing platform 2b and furthermore ventilation losses and wheel friction losses in the X direction can be detected by means of the disturbance force detection means 11 arranged between the carriage 1b and the weighing platform 2, be measured.

The weight forces of the cover unit 34 are directed in the Z-direction over the (substantially) frictionless floating bearings 8 in the shown foundation or the test bed frame la.

FIG. 6 further shows that the band unit frame 3a of the binding unit 34 holds two rollers 3c rotatably mounted. Around these rollers 3c, a continuous treadmill 3b is arranged (looped) so that it can be set in motion, for example, by a rotary movement of the rollers 3c. The treadmill 3b has a width at the cover tape unit 34 which is larger than that of the motor vehicle F to be tested. The test bed frame 1a may be rotatably supported around the Z axis to its surroundings (not shown).

In summary, it is made possible by the device described here that an increased measurement accuracy in combination with a fast and less complicated convertibility between different configurations of the test bed 1 are made possible.

The conversion according to the method described here, when converting from the five-band construction shown in FIG. 1 to a three-band or cover construction according to FIGS. 3 or 5, essentially comprises the steps of (preferably initially) removing the center band 32 and the first sub-platform 2 a become. Thereafter, the cover unit 34 can be mounted on the carriage when a cover configuration is to be established. The connections in terms of a power transmission between the carriage lb and the cover unit 34 need not be secured with additional effort, since the cover unit 34 preferably rests securely on the carriage lb due to the weight alone. It can be provided (mechanical) guides and the like., Which facilitate a precise and reproducible installation of the binding unit 34.

Media connections (6a, 6b) between the lower part of the test bench 1 and the cover unit 34, e.g. those for compressed air, water and electricity, are preferably also connected automatically when setting up the binding unit. For this purpose, suitable devices can be provided on the cover unit 34, the carriage 1b and / or both components. For example, self-aligning connections can be provided translationally in the X and Y directions, which can be fed to one another by means of a guide. Also self-locking quick-couplings can be provided, for example, in compressed air and water media connections.

In the case where a three-band configuration is to be constructed instead of a cover, the above-described step of setting up the tape unit 3 changes in that a center tape unit 32 and two side tape units 33 are mounted.

Other assembly work may include mounting the fastener 5 for the three-band configuration on the second sub-platform 2b if it has been disassembled for the five-band configuration.

The conversion according to the method described here, when converting from a three-band or cover construction according to FIGS. 3 or 5 to the five-band construction shown in FIG. 1, essentially comprises the above-explained steps in a different order. Thus, the tape unit (s) 3 of the Three-band or cover construction removed and possibly the fastening device (s) 5a. Then, the first sub-platform 2a and the middle-band unit 32 are set up, the first sub-platform 2a already carrying the (most important) subassemblies, such as the wheel-band units 31 and the sill supports 5b, pre-installed. As has already been described above, media connections and power connections are preferably connected to one another automatically when the center tape unit 32 and the first sub-platform 2a are placed on top, so that this does not have to be carried out manually.

In summary, the method allows a very quick retooling with reduced effort and can be carried out almost completely automated.

Reference character list

Test bench frame la

Sled lb

Motor vehicle F

Weighing platform 2

Tape unit 3

Wheel belt unit 31

ittenbandeinheit 32

Sideband units 33

Cover tape unit 34

Tape unit frame 3a

Treadmill 3b; Upper strand 3ba

Roll 3c

Tape unit bearing 3d

Force sensing means 4

Z-force sensing means 4a, X-force sensing means 4b, Y-force sensing means 4c sub-platforms: first 2a, second 2b

Fastening device 5

Holding system 5a; first fastening element 5aa; second fastening element 5ab

Fastening device 5b

Coupling interface 6

fluidic coupling interface 6a

electrical coupling interface 6b

Power transmission interface 6c

Connecting device 7

Swimming camp 8

Weighing pad 9

Bearing 10 for wheel R

Disturbance detection means 11

Claims

1. Wind ka na I test bench, in particular a multi-configuration Windkanalprüfstand which is convertible at least in a one-band, three-band and / or five-band configuration,

With

a test stand frame (1a) for absorbing forces,

a weighing platform (2), which is mounted relatively movable to the Prüfsta ndrahmen (la),

at least one force detecting means (4) arranged between the weighing platform (2) and the test rig frame (1a) for detecting forces between the weighing platform (2) and the test frame (1a), and

at least one belt unit (3) with a treadmill (3b) wound around two rollers (3c),

marked by

a carriage (1b) for receiving at least one belt unit (3) of a binding or three-band configuration, the carriage (1b) being mounted in the X and Y directions in a relatively movable manner relative to the test rig frame (1a).

2. Windkanalprüfstand according to claim 1, characterized in that the carriage (lb) and the weighing platform (2) are so coupled in the X and / or Y direction that a relative movement between the carriage (lb) and the weighing platform (2) is prevented in the associated direction.

3. wind tunnel test stand according to at least one of the preceding claims, characterized in that in a cover configuration, a cover tape unit (34) on the carriage (lb) is arranged.

4. Windkanalprüfstand according to at least one of the preceding claims, characterized in that in a three-band configuration at least two side band units (33) on the carriage (lb) are arranged.

A windscreen tester according to at least one of the preceding claims, characterized in that in the three or five band configuration, a center band unit (32) between wheel band units (31) of the five band configuration and sideband units (33) of the three band configuration on which the wheels of the examining motor vehicle (F) are provided, is provided

the center belt unit (32) is mounted on the carriage (lb) or stationary.

6. Windkanalprüfstand according to at least one of the preceding claims, characterized in that the carriage (lb) in the Z direction derives forces in an environment and is floatingly mounted in the X and Y directions.

7. Windkanalprüfstand according to at least one of the preceding claims, characterized in that the weighing platform (2) at least two sub-platforms (2 a, 2 b), which are mounted separably, wherein

at least one wheel-band unit (31) and a fastening device (5) of the five-band configuration are arranged on the first sub-platform (2a).

8. Windkanalprüfstand according to claim 7, characterized in that the at least one Radbandeinheit (31) and the at least one fastening means (5) are mounted displaceably and arretierbar on the first sub-platform (2a).

9. Windkanalprüfstand according to at least one of the preceding claims, characterized in that the weighing platform (2) at least two sub-platforms (2 a, 2 b), which are mounted separably, wherein

on the first sub-platform (2a) at least one Radbandeinheit (31) and a fastening means (5) of the five-band configuration are arranged pre-installed, and wherein

the at least two sub-platforms (2a, 2b) are interconnected in a five-band configuration of the wind tunnel test rig, while a first Partial platform (2a) is separated in a three-band or cover configuration of Windkanalprüfstandes of the second sub-platform (2b).

10. Windkanalprüfstand according to at least one of the preceding claims, characterized in that the Windkanalprüfstand has at least one fastening means (5) adapted to hold a motor vehicle (F) in a predetermined position on the treadmill (3b), wherein

in a five-band configuration of the wind tunnel test rig, the fastening device (5) is arranged on a first sub-platform (2a) of the weighing platform (2); and

in a three-band or cover configuration of the wind tunnel test rig, the fastening device (5) is arranged on a second sub-platform (2b) of the weighing platform (2).

11. wind tunnel test stand according to at least one of the preceding claims, characterized in that the first and second sub-platform (2a, 2b) at least one predefined coupling interface (6), wherein via the coupling interface (6) at least X, Y and Z forces between the first and second sub-platforms (2a, 2b) are transferable and preferably further fluidic media and electrical currents are transferable.

12. Windkanalprüfstand according to at least one of the preceding claims, characterized in that a fluidic coupling interface (6a) for the fluidic media have automatic quick couplings, the electrical coupling interfaces (6b) are mounted sliding self-aligning and power transmission interfaces (6c) have latching elements.

13. wind tunnel test stand according to at least one of the preceding claims, characterized in that the force sensing means (4) connecting the weighing platform (2) and the test rig frame (1), on the second sub-platform (2b) is arranged.

14. Windkanalprüfstand according to at least one of the preceding claims, characterized in that at least one Z-force detecting means (4a) between the test rig frame (1) and the weighing platform (2), in particular the second sub-platform (2b) is arranged with the at least Z- Forces are detectable.

15. wind tunnel test stand according to at least one of the preceding claims, characterized in that an interference force detecting means (11) between the carriage (lb) and the second sub-platform (2b) is arranged.

16. Windkanalprüfstand according to at least one of the preceding claims, characterized in that at least one bearing below an upper run (3ba) of the at least one treadmill (3b) of a belt unit (3) is arranged, wherein the bearing is a weighing pad (9), and wherein

the weighing pad (9) is arranged such that the motor vehicle (F), when fixed on the treadmill (3b), rests on the treadmill (3b) with the vehicle wheels above the at least one weighing pad (9), and wherein

the at least one weighing pad (9) detects forces in the z direction, in particular the weight force of the motor vehicle (F) and up and / or down forces.

17. Windkanalprüfstand according to at least one of the preceding claims, characterized in that the fastening means (5) holds the motor vehicle (F) on the treadmill (3b) in a fixed position, in particular above the at least one weighing pad (5), and

the fastening device (5) fixes the motor vehicle (F) such that forces in the X, Y and / or Z direction can be transmitted from the motor vehicle (F) via the fastening device (5) to the weighing platform (2).

18. A method of retrofitting a wind tunnel test rig according to at least one of the preceding claims, characterized in that the cover unit (34) is removed from the carriage (1b) for conversion from a three-band or cover configuration to a five-band configuration, the first sub-platform (2a) with pre-installed wheel belt units (31) and fastening device (5) is set up on the second sub-platform (2b), and a center belt unit (32) is positioned between the wheel belt units (31); or

for retrofitting from a five-band configuration to a one-band or three-band configuration, the center tape unit (32) is removed,

the first sub-platform (2a) with the mounted wheel-band units (31) and the fastening device (5) is removed from the second sub-platform (2b), and the band unit (3) of the one-band or three-band configuration is placed on the wind tunnel test bench.